Regarding the positive heat-resistant resin precursor compositions, the exposed portion of which dissolves in an alkaline developer, those prepared by adding a naphthoquinone diazide to a polyamic acid (Japanese Unexamined Patent Application Publication No. 52-13315, U.S. Pat. No. 4,093,461), those prepared by adding naphthoquinone diazide to a soluble polyimide having a hydroxyl group (Japanese Unexamined Patent Application Publication No. 64-60630, European Patent No. 264678A1), and those prepared by adding a naphthoquinone diazide to polyamide having hydroxyl groups and (Japanese Unexamined Patent Application Publication No. 56-27140, European Patent No. 23662A1) are known in the art.
In a composition containing a common polyamic acid and naphthoquinone diazide, the effect of naphthoquinone diazide that decreases the solubility in an alkaline solution is weak compared to the solubility of the carboxyl groups in the polyamic acid. Thus, a desired pattern cannot be obtained in most cases, which is a problem. In order to control the alkali solubility of the polyamic acid, a polyamic acid derivative in which a carboxyl group of the polyamic acid is protected by an ester group has been developed. However, in a composition containing this polyamic acid derivative and naphthoquinone diazide, the effect of the naphthoquinone diazide to decrease the solubility in an alkaline solution becomes excessively strong. As a result, although desired patterns can be obtained, a dramatic decrease in the sensitivity occurs, which is a problem.
To overcome this problem, the addition of compounds having various phenolic hydroxyl groups to the composition containing the polyamic acid derivative and naphthoquinone diazide has been proposed. Such an addition easily increases the sensitivity; however, the compound fly off during the curing process for forming a polyimide film, thereby increasing the shrinkage rate after curing. The two characteristics have been difficult to achieve simultaneously.